For much of the twentieth century, the American right was suspiciously absent from historians’ grand narratives of the United States. In the early Cold War, social scientists and political theorists held that the United States was exceptional. Because the United States was not born out of a feudal tradition, Louis Hartz famously argued, the country lacked the extremes of left and right that were found in Western Europe. A liberal consensus bound the nation together, for better or worse. National...